Well pressure sealing cup reinforcing structure

ABSTRACT

An improved reinforcing structure and method of making said structure are disclosed. The improved reinforcing structure is a polyfurcated cylinder having an integral base portion and a tines portion. The method of manufacture includes the steps of rolling a polyfurcated plate with an integral base and tines portion, rolling the base portion into a cylindrical shape and securing the abutting ends of the base.

United States Patent 1 1 [111 3,822,067

Berry et al. July 2, 1974 [5 WELL PRESSURE SEALING CUP 1,825,185 9/1931 Greenidge 277/212 (3 REINFORCING STRUCTURE 2,619,393 1 1 1952 Wilson et a1 92/241 2,723,721 11/1955 Corsette ..277/212C [75] Inventors: Robert F. Berry, Dallas; Henry W.

Blackwell, Venus, both of Tex. [73] Assignee: Dresser Idustries, Inc., Dallas, Tex. Primary Exammer samuel Rothberg Attorney, Agent, or Firm-William E. Johnson, Jr.; Mi-

[22] Filed: Jan. 8, 1973 chael J. Caddell; Morgan L. Crow [2]] Appl. No.2 321,622

Related US. Application Data 1 [57] ABSTRACT [62] Division of Ser. No. 166,171, July 26, 1971, Pat. No. 7

35722953- An improved reinforcing structure and method of v making said structure are disclosed. The improved re- [52] US. Cl. 277/181. i f i Structure i a polyfurcated cylinder having [51] Int. Cl..... F163 15/00 an integral base portion and a tines portion The [58] Field of Search 277/2l2 212 2121: 1 method of manufacture includes the steps of rolling a 277/ 181, 186; 92/240, 2 lyfurcated plate with an integral base and tines portion, rolling the base portion into a cylindrical shape References Cited and securing the abutting ends of the base.

UNITED STATES PATENTS 1,546,942 7/1925 Roth 277/186 13 Claims, 6 Drawing Figures CROSS REFERENCE TO RELATED APPLICATION BACKGROUND OF THE INVENTION The field of invention relates to well operations in which a swabbing operation may be performed. Swabbing generally is the removal of liquid from a well by means of a sealing element mounted on a tool and lowcred into a well by means of a wireline. The tool is lowered through a suitable amount of tubing and then lifted within the well effecting a seal with the pipe and lifting fluid above the tool to the surface. Packer cups are generally used to seal well pressure in one direction and are mounted on a well tool and positioned in a sealing engagement with well pipe. Packer cup application normally is a static or limited movement application.

There are a multitude of prior well swab bodies using a plurality of shaped wires held in base structures of various types as the reinforcing structure. See, for example, U.S. Pat. No. 2,887,347 issued to T. B. Losey. There are also prior well swabs employing metallic cones or corrugated cylinders as the reinforcing structure. See, for example, U.S. Pat. No. 1,898,292 issued to C. S. Crickmer and U.S. Pat. No. 2,013,903 issued to F. A. Thaheld. There are also prior well swabs employing slotted metallic cylinders as wear protective structures. See, for example, U.S. Pat. No. 2,619,393 issued to R. E. Wilson and .l. A. Wilson and U.S. Pat. No. 2,456,551 issued to R. A. Wilson.

Difficulty has been experienced in the past with such swab cup reinforcing structures constructed with a cylindrical base having upstanding tines or fingers pivot ally attached to the base. Lack of cantilevered support from'the base allowed the tines to become misaligned during the molding process, or required expensive fixtures and time consuming assembly of each finger.

Disadvantages with other unitary cup reinforcing structures madefrom tubular material are due to the time consuming machining operations and resultant high cost.

A primary object of this invention is to provide a methodand structure for an improved pressure sealing cup reinforcing structure.

A further object is to provide a method and structure for producing a pressure sealing cup reinforcing structure at lower cost.

A further object is to provide an intermediate subassembly reinforcement structure for a well pressure sealing cup.

SUMMARY OF THE INVENTION These and other objects of the invention are generally provided by a well pressure sealing cup reinforcing structure havinga body with a cylindrical base portion having a non-continuous periphery, the body having a plurality of integral, upstanding tines and by the method including the steps of rolling a polyfurcated plate having an integral base and tines portion rolling the base portion into a cylindrical shape and securing the base portion in the cylindrical shape. As an additional feature, an intermediate subassembly is provided 2 for use in a well pressure sealing cup including a unitary metallic plate with a first edge and an opposite edge and having a continuous portion along the first edge and integral tines extending from; the continuous portion to the opposite edge.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation view of an intermediate subassembly for constructing a well pressure sealing cup reinforcing structure according to this invention.

FIG. 2 is an end elevation view of the subassembly illustrated in FIG. 1.

FIG. 3 is a view partially in elevation and partially in cross section of a well pressure sealing cup reinforcing structure according to this invention.

FIG. 4A is a cross section view of the preferred embodiment taken at section line 4-4 in FIG. 3.

FIG. 4B is an alternative embodiment of FIG. 4A.

FIG. 4C is still another alternative embodiment of FIG. 4A.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates an intermediate subassembly according to this invention wherein a flat metallic plate of the general shape illustrated may be used to construct the reinforcing structure. The length of a first edge 10 is detennined as the approximate circumference for the base of the cup to be more fully described hereinafter. The opposite edge 14 from the first edge 10 is the starting point for sheared or sawed slots 16 which begin at opposite edge 14 and proceed to a point 18 near the first edge 10. With proper tooling known to those skilled in the art, all of the necessary multiplicity of slits 16 can be sheared or cut with a single stroke of a punch press although many other methods of manufacture are well known to those with skill in the art.

ities in the pipe (not shown) in which the cup will seal.

FIG. 3 illustrates a semi-finished reinforcing structure after continuous portion 24 has been rolled into a generally cylindrical shape. The outside diameter of cylindrical shape of continuous surface 24 is illustrated at 24 in FIG. 3. Straight portion 26 of the tines may be oriented parallel to central axis 34 or at an angle a of 0 to 15. Since the straight portion 26 is on a larger diameter than continuous portion 24, after forming contiriuous portion 24 into a cylindrical surface, there will be gaps between the tines since the circumference 'at a larger diameter 35 is greater than the circumference at diameter 24. The circumferential length of metal at di ameter 35 will be equal to the circumferential length of metal at diameter 24. However, since the circumference at diameter 35 is greater than the circumference at diameter 24, there wil be circumferential gaps at diameter 35 since the tine ormetalliic portion will subtend a smaller angle of are at the larger diameter than the same width of metal at the diameter at surface 24. The slots or gaps between the tines provide for exposure of the elastomer as subsequently molded around the reinforcing sturcture according to this invention whereby the elastomer may feed through the slots between the tines responsive to pressure internal to the cup to maintain a seal between the cup and the pipe in which it seals while the cup may be performing in a static condition as a packer cup or in a dynamic condition as a swab cup. A cylindrical ring 36 may be placed in encircling relationship to cylindrical surface 24 to reinforce the structure and contain the base to prevent outward movement responsive to internal pressure in the finished cup. Tines 28 are thus cantilevered from continuous portion 24 and are flexible at the free end 38 which was originally the opposite edge 14 in FIG. 1.

American Petroleum Institute (API) tubing and casing threads represent the largest usage of threaded connections used in oil and gas wells. The basic distance is 1 inch between the ends of two pieces of pipe with API tubing or casing threads threaded into a coupling and tightened with the proper torque. Manufacturing tolerances can allow a particular joint dimension to vary plus or minus .5 inches, i.e. between .5 and 1.5 inches. Since the maximum allowable distance between the end of pipes in a joint is 1.5 inches, the straight portion of a well pressure sealing cup should be at least 1.5 inches so the cup may enter the end of one piece of pipe before leaving the end of the adjacent piece of pipe. A cup too short to span the gap between pipes could move laterally into the larger inside diameter of the coupling and allow the cup to become hung in the gap and could allow the cup to lose sealing engagement with the pipe.

FIG. 4A illustrates the section 44 of FIG. 3. In FIG. 1, ends 42 and 44 of continuous portion 24 are brought together as illustrated in FIG. 4A at joint 40. In this embodiment the continuous portion 24 is rolled into a substantially 360 cylindrical surface to form the reinforcing structure for a pressure sealing well packer cup or swab cup. The joint 40 may subsequently be reinforced by the continuous ring 36 or it may be welded together.

DESCRIPTION OF ALTERNATE EMBODIMENTS FIG. 43 illustrates an alternate embodiment in which a plate with a first edge long enough to form onehalf the circumference of the base of a reinforcing structure is used. Two such base segments may each be formed into a 180 of cylindrical arc and then assembled with two joints as at 46 and 48 in FIG. 48 to form a completed reinforcing structure. Joints 46 and 48 may be reinforced by the addition of a ring 36 or each joint may be welded.

FIG. 4C illustrates another alternative in which each piece of reinforcing structure forms one-third of the base circumference so that three pieces are used to form a completed structure. The three segments are then assembled with three joints as at 50, 52, and 54 and may be reinforced by addition of ring 36, Alternative embodiments as illustrated in FIGS. 4B and 4C may lend themselves more readily to single stroke forming in a punch press operation and thereby offer economies of manufacture.

After considering these examples, skilled persons will understand that variations may be made without departing from the principles disclosed and I contemplate the employment of any structures, arrangement, or modes of manufacture that are properly within the scope of the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An improved well swab reinforcing structure comprising a body having a cylindrical base portion and a tines portion, the improvement comprising:

said body having a unitary cylindrical plate with a first edge and an opposite edge, a continuous portion along said first edge, and slits cut from said opposite edge toward said first edge;

said plate having bends running parallel to said first edge; and

said continuous portion further comprising a cylindrical section.

2. Apparatus according to claim 1 further comprising a continuous ring surrounding said cylindrical section.

3. Apparatus according to claim 1 wherein said cylindrical section is joined by welding to form a continuous cylindrical section.

4. A well swab reinforcing structure comprising:

an annular cylindrical base portion;

a plurality of upstanding tines integral with said base portion;

' said annular base portion comprising a single, circularly curved section of plate joined at its two ends; and,

said tines comprising an axially extended bent portion of said plate having axial slots cut therein.

5. Apparatus according to claim 4 wherein said bends in said tines are parallel to said base portion of said flat plate.

6. A well pressure sealing cup reinforcing structure comprising:

a body having a central axis and cylindrical base portion with a broken periphery on a first diameter, and said body having a plurality of upstanding tines integral with said base portion.

7. Apparatus according to claim 6 wherein said broken base portion has one peripheral gap.

8. Apparatus according to claim 6 wherein said broken base portion has a plurality of peripheral gaps.

9. Apparatus according to claim 6 wherein a portion of said tines are on a second diameter larger than said first diameter.

10. Apparatus according to claim 6 wherein said tines have a substantially straight portion at least 50% of the length of said tines.

11. Apparatus according to claim 10 wherein said straight portion is at 0 to 15 angle to said central axis.

tines are substantially rectangular in cross section. 

1. An improved well swab reinforcing structure comprising a body having a cylindrical base portion and a tines portion, the improvement comprising: said body having a unitary cylindrical plate with a first edge and an opposite edge, a continuous portion along said first edge, and slits cut from said opposite edge toward said first edge; said plate having bends running parallel to said first edge; and said continuous portion further comprising a cylindrical section.
 2. Apparatus according to claim 1 further comprising a continuous ring surrounding said cylindrical section.
 3. Apparatus according to claim 1 wherein said cylindrical section is joined by welding to form a continuous cylindrical section.
 4. A well swab reinforcing structure comprising: an annular cylIndrical base portion; a plurality of upstanding tines integral with said base portion; said annular base portion comprising a single, circularly curved section of plate joined at its two ends; and, said tines comprising an axially extended bent portion of said plate having axial slots cut therein.
 5. Apparatus according to claim 4 wherein said bends in said tines are parallel to said base portion of said flat plate.
 6. A well pressure sealing cup reinforcing structure comprising: a body having a central axis and cylindrical base portion with a broken periphery on a first diameter, and said body having a plurality of upstanding tines integral with said base portion.
 7. Apparatus according to claim 6 wherein said broken base portion has one peripheral gap.
 8. Apparatus according to claim 6 wherein said broken base portion has a plurality of peripheral gaps.
 9. Apparatus according to claim 6 wherein a portion of said tines are on a second diameter larger than said first diameter.
 10. Apparatus according to claim 6 wherein said tines have a substantially straight portion at least 50% of the length of said tines.
 11. Apparatus according to claim 10 wherein said straight portion is at 0* to 15* angle to said central axis.
 12. Apparatus according to claim 6 further comprising a continuous cylindrical ring encircling said base portion.
 13. Apparatus according to claim 6 wherein said tines are substantially rectangular in cross section. 